The present invention relates to devices for measuring the tension on a web of a printing press.
It has been desirable to measure the tension of a paper web on a printing press since the web may break during printing in the presence of excessive tension on the web. In the past, a rope was placed over the roll to be measured, and a known weight was suspended by the rope in order to measure this tension. It was necessary to calibrate the web lead in this manner for every different web that was used during a press run or on a new press run. This procedure was time consuming and inconvenient to the operators in the press room.
The current commercial available web tension measuring device thus required a calibration for every web lead around the sensing roller. Some of the requirements in the modern high speed web-fed press operation, especially printing, are variety and flexibility in the web lead configuration. Under this condition, the full time web tension measurements at some desirable locations of the press are impractical due to the routine calibrations.